Very easy install. I replaced both the vents in my 350. Takes some time because you have to scrape the old calking off and remove all the screws (probably 30 screws holding them in)
Make sure you get some self-leveling dicor caulk to seal it back up. You'll need two tubes to really do it right. Amazon, Camping World and lots of other online places sell it. This is the same stuff they use at the factory.
As to getting power to a fan there are probably already power wires there. In the unlikely event that there arn't power wires there you can get power from a nearby celing light. It's easy to push a fiberglass wire pull rod (get one cheap at harbor freight) through the styrofoam in the celing from the fan location over to a nearby lamp. And pull some power wires back. But I'll bet you a beer there are already power wires at the fan location.
2008 Georgetown SE 350DS BunkHouse